Use this forum if you have installed hMailServer and want to ask a question related to a production release of hMailServer. Before posting, please read the troubleshooting guide. A large part of all reported issues are already described in detail here.

Hello, as Amazon EC2 instances don't have the SMTP service installed, I wanted to send emails from my ASP.NET application via hMailServer instead. I've installed it successfully and opened port 25 in my Windows Firewall and EC2 Security Group. I have not configured anything special in the hMailServer admin console and I get this error when trying to send email from my ASP.NET application:

"Unable to read data from the transport connection: net_io_connectionclosed."

After som Googleing this error message seems to be related to unreachable / unconnectable mailserver.

Any ideas what's wrong? Do I need to configure a domain in the hMailServer admin?

I found out that the Auto-Ban was enabled in hMailServer, and my ip address was auto-banned.

I went under Settings > Advanced > Ip ranges, and found out that my ip address was in the autoban list, i removed my IP Address from there, and also disabled auto-ban as i dont require auto-ban, and it started working, and i am nomore getting the net_io_connectionclosed error.

I'm having a similar issue. I have written a c# application that needs to be able to send out emails via an SMTP server that I can control. The application doesn't need to do anything with the SMTP server other than use it to send emails. To that end I don't need to receive via the hMailServer - just send. That may change as I learn more about mail servers but for right now I'd be happy with it sending emails.

I admit I'm still trying to get through the documentation trying to figure out what is the least configuring I can do to support SMTP. I was receiving an authentication error until I disabled Auto-banning. That's when I started getting:

Unable to read data from the transport connection: net_io_connectionclosed.

Any suggestions on what the least I can get away with configuration-wise to support SMTP would be helpful and why I can't get past the above listed error would be very helpful!

One other note of interest. I would like to be able to run hMailServer off of my laptop running windows 7 in my home using cable internet access. So I'm not running on a swanky server or on a dedicated internet connection. Very garage startup situation happening here. Thanx!

My apologies. I figured I had the same problem so I'd pick up the torch. I like the idea of using IIS/SMTP server, though. Sounds simpler. The problem I'm finding is that there is no SMTP server in IIS 7.5 on Windows 7. Or atleast I can't find it anywhere.

patelharshilb wrote:I found out that the Auto-Ban was enabled in hMailServer, and my ip address was auto-banned.

I went under Settings > Advanced > Ip ranges, and found out that my ip address was in the autoban list, i removed my IP Address from there, and also disabled auto-ban as i dont require auto-ban, and it started working, and i am nomore getting the net_io_connectionclosed error.

Thanks! This solved my issue. I was able to send out a few emails and then suddenly I started getting the net_io_connectionclosed error. Ineed, hMailServer auto banned me and this solved it.